mathschallenge.net

Problem

There are seven ways a 3x2 block can be placed inside a rectangle measuring 4x3.

How many ways can a 3x2 block be placed inside a rectangle measuring 8x6?

Solution

Consider the diagrams.

1st diagram: 7 4 = 28 positions for the block.
2nd diagram: 6 5 = 30 positions.

Giving 28 + 30 = 58 different positions for 3x2 block on an 8x6 rectangle.

How many positions can a 3x2 block be placed on an m x n rectangle?
What about different sized blocks?